Hi, Femilon contains both ethinyl estradiol and desogestrel which is used to prevent pregnancy and irregular periods. It helps in preventing the release of the egg. It also prevents the egg s fertilization by the sperm. It may also help to reduce the risk of ovarian cancer. Side effects of Femilon are nausea, vomiting, headache, dizziness, sweating, indigestion, abdominal pain, GIT upset, changes in bowel habits, breast tenderness and enlargement, irregular uterine bleeding, facial hair growth, acnes, delayed wound healing, mood swings, depression, dizziness, fatigue, tiredness, weakness, changes in weight, vaginal bleeding, vaginal discharge, changes in sexual desire, loss of appetite, dry mouth, difficulty in micturition, changes in sleep pattern, dizziness, easily bruising or bleeding, allergic reactions etc. If these side effects persist for long or bother you, you should consult your doctor promptly for medical help. You can use condoms or contraceptive pills or both for preventing pregnancy. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician